Patent US2217265A successfully refreshed from Google Patents.
Patent US3907535A successfully refreshed from Google Patents.
US3907535A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process of making a partially crystallizable seal
Assignee: Schott AG
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Filing: 1974-03-21
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Granted: 1975-09-23
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Expires: 1994-03-21
Abstract
Abstract Soldering glass compositions which can be soldered to form airtight joints having a high mechanical strength are provided by employing an admixture of a thermally devitrifiable solder glass and an inert refractory compound having a negative coefficient of thermal expansion which are characterized by precipitating crystals upon soldering in a volume not greater than half the soldering glass volume, thereby avoiding the adverse effects of crystallization on flowability of the soldering composition and permitting loading with high proportions of the refractory compound.
Inventors
- 👤 Gerd Muller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 07:28
CPC Classifications
C; C03; C03C; C03C27/00; C03C10/00; C03C10/0054; C03C27/06; C03C27/10; C03C3/00; C03C3/04; C03C3/062; C03C3/07; C03C3/072; C03C8/00; C03C8/24; C03C8/245; C04; C04B; C04B37/00; C04B37/003; C04B37/005; C04B2237/00; C04B2237/02; C04B2237/10; C04B2237/30; C04B2237/32; C04B2237/34; C04B2237/343; C04B2237/50; C04B2237/70; C04B2237/708
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
76 words
IN A PROCESS FOR SOLDERING WITH A SOLDER GLASS COMPOSITION COMPRISING A TERMALLY DEVITRIFIABLE SOLDER GLASS AND AN INERT REFRACTORY COMPOUND HAVING A NEGATIVE COEFFICIENT OF THERMAL EXPANSION, THE IMPROVEMENT WHICH COMPRISES DISCONTINUING THE SOLDERING BEFORE 50 PERCENT OF THE TOTAL VOLUME OF SAID COMPOSITION CRYSTALLIZES, AND WHEREIN SAID COMPOSITION CONSISTS ESSENTIALLY OF A. A THERMALLY DEVITRIFIABLE GLASS HAVING A SOFTENING POINT OFABOUT 300*-380*C, SAID SOLDER GLASS HAVING THE FOLLOWING COMPOSITION ( IN PERCENT BY WEIGHT):
Claim 2
Dependent Claim
76 words
IN A PROCESS FOR SOLDERING WITH A SOLDER GLASS COMPOSITION COMPRISING A TERMALLY DEVITRIFIABLE SOLDER GLASS AND AN INERT REFRACTORY COMPOUND HAVING A NEGATIVE COEFFICIENT OF THERMAL EXPANSION, THE IMPROVEMENT WHICH COMPRISES DISCONTINUING THE SOLDERING BEFORE 50 PERCENT OF THE TOTAL VOLUME OF SAID COMPOSITION CRYSTALLIZES, AND WHEREIN SAID COMPOSITION CONSISTS ESSENTIALLY OF A. A THERMALLY DEVITRIFIABLE GLASS HAVING A SOFTENING POINT OFABOUT 300*-380*C, SAID SOLDER GLASS HAVING THE FOLLOWING COMPOSITION ( IN PERCENT BY WEIGHT):
Claim 3
Dependent Claim
29 words
A process according to claim 1, said solder glass consisting of PbO, B2O3, SiO2 and Al2O3 wherein up to 15 percent of the oxygen is optionally replaced by fluorine.
Claim 4
Dependent Claim
18 words
A process according to claim 1, said composition consisting essentially of about 15-30 percent by weight pulverized beta-eucryptite.
Claim 5
Dependent Claim
16 words
A process according to claim 3, said solder glass consisting essentially of in percent by weight:
Claim 6
Dependent Claim
22 words
A process according to claim 1, said composition being about 80 percent by weight solder glass and 20 percent by weight beta-eucryptite.
Claim 7
Dependent Claim
65 words
A process according to claim 1, comprising soldering an aluminum oxide ceramic at a temperature of about 450*C. with a solder glass composition consisting essentially of: a. about 80 percent by weight of a soldering glass consisting essentially of PbO, B2O3, SiO2 and Al2O3 wherein up to 15 percent of the oxygen is optionally replaced by fluorine; and b. about 20 percent by weight beta-eucryptite.
Claim 8
Dependent Claim
37 words
A process according to claim 1, comprising soldering glasses which have a thermal expansion coefficient of about 30 X 10 7 to 50 X 15 7 per * C. at a temperature of up to 600* C.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-09-22 | 1979-03-24 | 1979-09-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-22 | 1983-03-24 | 1983-09-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-22 | 1987-03-24 | 1987-09-23 | $7700.00 | Window Closed / Lapsed |